Qt工作笔记-QML界面与QWidgets界面相互交互

C++要做的事情：

1.QML中注册C++类型（qmlRegisterType）

2.获取元对象树，从中提取注册的指针【这样就和普通的对象一样了】

qml要做的事情：

1.import注册的C++类型

2.使用onXXX进行qml与C++的交互

通过Q_PROPERTY进行交互

-----------------------------------------------------------

因为qml启动开销大，第一次是创造界面，然后在第二次，第三次等仅仅是隐藏，并没有销毁窗口；

程序运行截图如下：

源码如下：

test.h

#ifndef TEST_H
#define TEST_H

#include <QObject>

class Test : public QObject
{
    Q_OBJECT
public:
    explicit Test(QObject *parent = 0);
    Q_PROPERTY(QString msg READ msg WRITE setMeg NOTIFY msgChanged)
    Q_PROPERTY(QString close READ close WRITE setClose NOTIFY closeChanged)
    QString msg();
    QString close();
    void setClose(QString close);
    void setMeg(QString msg);
signals:
    void msgChanged();
    void aquireData(QString msg);
    void closeChanged();

    void hideQMLWindow();


private:
    QString m_msg;
};

#endif // TEST_H

widget.h

#ifndef WIDGET_H
#define WIDGET_H

#include <QWidget>
class QQmlApplicationEngine;
class Test;

namespace Ui {
class Widget;
}

class Widget : public QWidget
{
    Q_OBJECT

public:
    explicit Widget(QWidget *parent = 0);
    ~Widget();


public slots:
    void btnClicked();
    void getMes(QString msg);
    void closeQML();

private:
    Ui::Widget *ui;
    QQmlApplicationEngine *m_engine;
    Test *m_test;

    bool m_windowShow;
    bool m_realLoad;
};

#endif // WIDGET_H

main.cpp

#include "widget.h"
#include <QApplication>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    Widget w;
    w.show();

    return a.exec();
}

test.cpp

#include "test.h"
#include <QDebug>

Test::Test(QObject *parent) : QObject(parent)
{

}

QString Test::msg()
{
    return "";
}

QString Test::close()
{

}

void Test::setClose(QString close)
{
    Q_UNUSED(close)
    emit closeChanged();
    emit hideQMLWindow();
}

void Test::setMeg(QString msg)
{
    emit aquireData(msg);
}

widget.cpp

#include "widget.h"
#include "ui_widget.h"
#include "test.h"
#include <QDebug>
#include <QQmlApplicationEngine>
#include <QQuickView>
#include <QList>
#include <typeinfo>


Widget::Widget(QWidget *parent) :
    QWidget(parent),
    ui(new Ui::Widget)
{
    ui->setupUi(this);
    m_realLoad=false;
    m_windowShow=false;
    m_engine=new QQmlApplicationEngine;
    connect(ui->pushButton,SIGNAL(clicked(bool)),this,SLOT(btnClicked()));
}

Widget::~Widget()
{
    delete ui;
}

void Widget::btnClicked()
{
    if(m_windowShow){
        return;
    }
    if(m_realLoad){
        qDebug()<<"开启";
        m_test->setClose("开启");
        return;
    }
    qmlRegisterType<Test>("Test",1,0,"Test");
    m_engine->load(QUrl(QLatin1String("qrc:/example.qml")));
    QList<QObject*> qmlList=m_engine->rootObjects();
    QObjectList list=qmlList[0]->children()[0]->children();
    for(int i=0;i<list.size();i++){
        if(QString(typeid(*list[i]).name()).contains("Test")){
            m_test=qobject_cast<Test*>(list[i]);
            connect(m_test,SIGNAL(aquireData(QString)),this,SLOT(getMes(QString)));
            connect(m_test,SIGNAL(deleteQMLWindow()),this,SLOT(closeQML()));
            m_windowShow=true;
            m_realLoad=true;
            break;
        }
    }
}

void Widget::getMes(QString msg)
{
    QStringList list=msg.split(";");
    for(int i=0;i<list.size();i++){
        ui->plainTextEdit->insertPlainText(list[i]+"\n");
    }
    ui->plainTextEdit->insertPlainText("---------------------\n");
    m_windowShow=false;
}

void Widget::closeQML()
{
    m_windowShow=false;
}

example.qml

import QtQuick 2.5
import QtQuick.Window 2.2
import Test 1.0
import QtQuick.Controls 1.4


Window {
    id:window
    visible: true
    width: 240
    height: 100
    title: qsTr("QML数据发出窗口")
    onClosing: {
        test.close="close"
        window.hide()
    }

    Column{
        spacing:2
        Row{
            spacing:2
            Label{
                text:"姓名:"
                font.pixelSize: 22
                font.italic: true
            }
            TextEdit{
                id:name
                width:240
                font.pixelSize: 20
            }
        }
        Row{
            spacing:2
            Label{
                text:"性别:"
                font.pixelSize: 22
                font.italic: true
            }
            TextEdit{
                id:sex
                width:240
                font.pixelSize: 20
            }
        }
        Row{
            spacing:2
            Label{
                text:"年龄:"
                font.pixelSize: 22
                font.italic: true
            }
            TextEdit{
                id:age
                width:240
                font.pixelSize: 20
            }
        }
        Button{
            id:submit
            width:240
            text: qsTr("提交")
            onClicked:{
                test.msg="姓名："+name.text+";"+"性别："+sex.text+";"+"年龄："+age.text
                window.hide();
            }
        }

        Test{
            id:test
            onCloseChanged:{
                window.show()
            }

        }

    }
}